It has long been desired to produce bulk sweeteners exhibiting a combination of properties including sweetness, high humectancy (hygroscopicity), non-cariogenicity, crystallization inhibition and potential use for diabetics. Such sweeteners are useful in the manufacture of non-cariogenic and diabetic foods and confections, baked goods, animal foods, oral hygiene products and pharmaceuticals.
Although there are bulk sweeteners which meet some of the above requirements, none of them have all the desired characteristics and all have certain deficiencies. Sucrose, fructose and other sugars, although they have intense sweetness, are cariogenic and have only low humectancy.
One type of sweetener which meets many of the above requirements is conventional maltitol syrups. Some of these contain over 60% maltitol and are prepared by the hydrogenation of conventional high maltose syrups having over 60% maltose and only a minimum of glucose, generally less than 10% and most commonly less than 5%. However, thus prepared maltitol syrups are low in sorbitol, a component which has both high humectancy and sweetness. In order to improve the humectancy and sweetness of these products, they may require further compounding with addition of sorbitol. The maltitol compositions claimed herein are improvements over prior, conventional maltitol syrups since they inherently provide desired combinations of sweetness and humectancy, thus eliminating the need of additional compounding with sorbitol.
The preparation of conventional high maltose syrups is described in the prior art. For example, U.S. Pat. Nos. 3,795,584 and 3,804,715 assigned to Hayashibara show the saccharification of liquified starch to produce high maltose solutions using beta-amylase and alpha-1,6-glucosidase (pullulanase). However, such sugar compositions contain a maximum of a few percent of glucose.
CPC International U.S. Pat. No. 3,565,765 also teaches the formation of high maltose syrups using a combination of enzymes. This patent teaches the simultaneous use of a maltogenic enzyme and pullulanase to form high maltose syrups. While higher glucose levels than the Hayashibara patents are reported, the maximum amounts shown are less than 10%, generally less than 5%, and the sugars having a degree of polymerization of three or more are most frequently over 10%.
Another patent showing the enzymatic conversion is the A. E. Staley U.S. Pat. No. 3,791,865. It teaches the use of a mixture of beta-amylase and amylo-1,6-glucosidase to form high maltose syrups having small, even trace, amounts of glucose and having maltotriose contents of greater than 18%. CPC International's U.S. Pat. No. 3,549,496 shows the conversion of partially hydrolyzed starch into compositions containing maltose and up to 45% of glucose using Bacillus polymyxa amylase in a first conversion followed by glucoamylase. Such products have comparatively low maltose concentrations and high concentrations of saccharides having a degree of polymerization of three or more.
Other patents which show the production of high maltose compositions include Hayashibara U.S. Pat. Nos. 3,832,285 and 4,032,403; AB Stadex U.S. Pat. No. 3,996,107; Meiji Seika Kaisha U.S. Pat. No. 3,998,696; and CPC International U.S. Pat. No. 4,113,509.